Malicious PDF — malware analysis report

Static analysis result for SHA-256 3791cbfa24686b13…

MALICIOUS

PDF

74.6 KB Created: 2021-09-17 23:59:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 6b0aacbafbd5a15894f03ac87b8f1f87 SHA-1: 0e868419f88d65af2cba198ff9b1e049918e7aaa SHA-256: 3791cbfa24686b1338eee2459c3b77b2bd70339f8bd389cd6edfaee0c16e58fe
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF was flagged by ML classifiers and ClamAV as malicious, with heuristics indicating it functions as a link farm. While no scripts were explicitly extracted, the presence of numerous embedded URLs, many pointing to potentially disposable domains, suggests an attempt to redirect users to malicious content. The document body is heavily obfuscated, preventing a clear understanding of its specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9980

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://www.domaine-boussard-chablis.fr/ckfinder/userfiles/files/73979338837.pdf In PDF document text
    • https://bokaichenyu.com/upload/files/37932442998.pdfIn PDF document text
    • http://fxlcd.com/upload/file/25710025662.pdfIn PDF document text
    • http://ks-system.co.uk/ckfinder/userfiles/files/29911591665.pdfIn PDF document text
    • http://bangkokmagnetwire.com/ecodev_test/image_system/files/96435480069.pdfIn PDF document text
    • http://parkingparts.com/Upfiles/file/nogojojuxofunujituduxuz.pdfIn PDF document text
    • http://plaschke-partner.com/uploaded/file/luziresexim.pdfIn PDF document text
    • http://evrofurnitura.by/elax-furnitura.ru/uploads/files/12820924772.pdfIn PDF document text
    • http://xn--9n2bn9mz3aba29g44r4o0a.kr/fckeditor/userfiles/image/98307116170.pdfIn PDF document text
    • http://www.smartlandgroup.com/ckfinder/userfiles/files/71868157478.pdfIn PDF document text
    • http://bindashnews.com/userfiles/file/44700177392.pdfIn PDF document text
    • http://www.gobarging.com/uploads/textareas/file/32334882024.pdfIn PDF document text
    • http://qianxish.com/ckfind_image/files/sewede.pdfIn PDF document text
    • https://dzido.pl/userfiles/file/bokozodemagijepavavowori.pdfIn PDF document text
    • http://ilovechardonnayhills.com/userimages/776095592.pdfIn PDF document text
    • https://nacionalequipamentos.com/ckeditor/uploads/files/silafurirebajexosexewogeb.pdfIn PDF document text
    • https://sellos-mecanicos.com/wp-content/plugins/super-forms/uploads/php/files/b17ca1c34a2920697949f4e8210a9f44/17917493740.pdfIn PDF document text
    • https://dogathermalhotel.com/resimler/files/1284236528.pdfIn PDF document text
    • https://trieurodata.ro/images/file/19878889481.pdfIn PDF document text
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/161432c6b19340---jetevilezoretewirone.pdfIn PDF document text
    • https://360clothing.indicsys.com/home/www360cl/public_html/uploads/images/files/82940832411.pdfIn PDF document text
    • https://openkomm.yussfone-crm.com/userfiles/file/76476258137.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=pokemon+fire+red+new+version+gba+downloadPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c038.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC038 16340 bytes
SHA-256: 847403090beefee2a250f4abb24a85979ee815463dac71af16b5f6a80413708d
font_01_sfnt_off0000eab5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEAB5 10984 bytes
SHA-256: 68a3d36021c5e83ba945a3c71017d62e90416ea64d36b28f30e62ac208b9d67b
font_02_sfnt_off0001040b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1040B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1